It is feasible although very unlikely that a cat owner, or more likely her children, might get tapeworms from a flea that they’d removed from their cat by flea combing or because of a flea infestation in the home. I’ll map out the potential scenario as to how it might happen.
You are the mother of two young children. You’re in bed or sitting on a chair. Your cat is on your lap and you are diligently and carefully flea combing her. Nice work. Should be a daily treat for your cat. Your home is flea-free.
You comb-out a single flea. Normally you are able to crush the flea with the nail of your thumb against the flea comb or by some other means but on this occasion the flea immediately jumps off onto the bed or the floor avoiding death. You can’t see it as they are very small (although some individual fleas are actually quite large).
So, you have at least one flea in your home. You might have thousands of them if you have a flea infestation and ten cats. But I am painting a picture of a nearly flea-free home but a home in which the family cat is allowed outside to hunt. The family cat catches mice and mice have fleas. The fleas jump from the mice to your cat who brings them into the home inside her fur.
At this point you have a loose flea jumping around your home or settling down into the carpet or inside your bedding. Your child joins you on the bed to interact and play and to receive a bit of your love and attention.
As she crawls over the bed, that lone flea jumps onto her hand. She has no idea that it is there. She places her finger in her mouth as kids do. At that precise moment the flea is on her finger and it ends up in her mouth.
The flea is swallowed. Inside the flea is a larval tapeworm (cysticercoid) of the common tapeworm of cats and dogs: Dipylidium caninum. The larval tapeworm is inside the adult flea because the egg packets hatch inside the flea larvae so that the mature adult flea carries infective cysticercoids. These develop into tapeworms inside the human who has swallowed the flea.
The segments of tapeworm are passed in the faeces and into the toilet. End of cycle. Regarding the cat, the tapeworm segments emerge from the anus and fall to the floor to release egg packets. Flea larvae ingest the egg packets and keep the cycle going.
SOME MORE ON THE DAMNABLE FLEA: